diff options
Diffstat (limited to 'hw/nx-rng.c')
| -rw-r--r-- | hw/nx-rng.c | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/hw/nx-rng.c b/hw/nx-rng.c new file mode 100644 index 0000000..9cc5317 --- /dev/null +++ b/hw/nx-rng.c @@ -0,0 +1,99 @@ +/* Copyright 2013-2015 IBM Corp. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or + * implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + + + +#include <skiboot.h> +#include <xscom.h> +#include <io.h> +#include <cpu.h> +#include <nx.h> + +void nx_create_rng_node(struct dt_node *node) +{ + u64 bar, cfg; + u64 xbar, xcfg; + u32 pb_base; + u32 gcid; + u64 rng_addr, rng_len, len; + struct dt_node *rng; + int rc; + + gcid = dt_get_chip_id(node); + pb_base = dt_get_address(node, 0, NULL); + + if (dt_node_is_compatible(node, "ibm,power7-nx")) { + xbar = pb_base + NX_P7_RNG_BAR; + xcfg = pb_base + NX_P7_RNG_CFG; + } else if (dt_node_is_compatible(node, "ibm,power8-nx")) { + xbar = pb_base + NX_P8_RNG_BAR; + xcfg = pb_base + NX_P8_RNG_CFG; + } else { + prerror("NX%d: Unknown NX type!\n", gcid); + return; + } + + rc = xscom_read(gcid, xbar, &bar); /* Get RNG BAR */ + if (rc) + return; /* Hope xscom always prints error message */ + + rc = xscom_read(gcid, xcfg, &cfg); /* Get RNG CFG */ + if (rc) + return; + + /* + * We use the P8 BAR constants. The layout of the BAR is the + * same, with more bits at the top of P8 which are hard wired to + * 0 on P7. We also mask in-place rather than using GETFIELD + * for the base address as we happen to *know* that it's properly + * aligned in the register. + * + * FIXME? Always assusme BAR gets a valid address from FSP + */ + rng_addr = bar & NX_P8_RNG_BAR_ADDR; + len = GETFIELD(NX_P8_RNG_BAR_SIZE, bar); + if (len > 4) { + prerror("NX%d: Corrupted bar size %lld\n", gcid, len); + return; + } + rng_len = (u64[]){ 0x1000, /* 4K */ + 0x10000, /* 64K */ + 0x400000000, /* 16G*/ + 0x100000, /* 1M */ + 0x1000000 /* 16M */} [len]; + + + prlog(PR_INFO, "NX%d: RNG BAR set to 0x%016llx..0x%016llx\n", + gcid, rng_addr, rng_addr + rng_len - 1); + + /* RNG must be enabled before MMIO is enabled */ + rc = xscom_write(gcid, xcfg, cfg | NX_P8_RNG_CFG_ENABLE); + if (rc) + return; + + /* The BAR needs to be enabled too */ + rc = xscom_write(gcid, xbar, bar | NX_P8_RNG_BAR_ENABLE); + if (rc) + return; + rng = dt_new_addr(dt_root, "hwrng", rng_addr); + if (!rng) + return; + + dt_add_property_strings(rng, "compatible", "ibm,power-rng"); + dt_add_property_cells(rng, "reg", hi32(rng_addr), lo32(rng_addr), + hi32(rng_len), lo32(rng_len)); + dt_add_property_cells(rng, "ibm,chip-id", gcid); +} |